High color rendering single-source white-light emission: Characteristics of double perovskite Cs2NaYCl6: Sb3+/Tb3+/Mn2+

In the pursuit of environmentally friendly luminescent materials, lead-free double perovskites (LFDPs) have emerged as a promising candidate, distinguished by their unique photophysical characteristics. Concurrently, the development of a single-component phosphor capable of generating stable, full-spectrum white light presents a formidable challenge, standing in contrast to the prevalent multi-phosphor systems used in contemporary white light-emitting diodes (WLEDs). Here, we report the design and synthesis of a triple-doped Cs 2 NaYCl 6 : Sb 3+ , Tb 3+ , Mn 2+ material, achieving single-phase white light emission. In contrast to the pristine Cs 2 NaYCl 6 host, which displays only weak sky-blue luminescence, a remarkable augmentation in the intensity of its self-trapped exciton (STE) emission is observed upon Sb 3+ doping. The enhanced STE-based emission can be primarily attributed to the novel sensitizing state introduced by Sb 3+ doping. The effective STE energy transfer to Tb 3+ and Mn 3+ under Sb 3+ sensitization overcomes the inherent drawbacks of efficiency and color rendition in single-matrix WLEDs. The white light emission can be precisely tuned by simply adjusting the doping ratios. A WLED device was fabricated by integrating the as-synthesized phosphor with a 340 nm UV chip. The device exhibited promising white light performance, yielding a correlated color temperature (CCT) of 5133 K, a color rendering index (CRI) of 92.1, and CIE coordinates of (0.3422, 0.3587), thereby validating its strong potential for practical white lighting applications.